High-speed all-relay pulse counter



Get. 17, 1967 R. PRICHARD 3,348,204

HIGH-SPEED ALL-RELAY PULSE COUNTER Filed Dec. 50. 1963 CONTROL RELAYE:

DEClM AL. DU'T PUT ENARY OUTPUT INVENTOR.

ROY PR\CHARD BY Z ATTORNEY United States Patent 3,348,204 HIGH-SPEEDALL-RELAY PULSE COUNTER Roy Prichard, Lockport, Ill., assignor toInternational Telephone and Telegraph Corporation, New York, N.Y., acorporation of Maryland Filed Dec. 30, 1963, Ser. No. 334,248 12 Claims.(Cl. 340-168) ABSTRACT OF THE DISCLOSURE A high speed relay pulsecounter is provided. High speed as Well as reliability and economy areobtained by providing a counting chain in which only one counting relayoperation or only one counting restoration takes place during each pulseinterval or each inter-pulse interval. An ideal pulse receiving rate isobtained in this way, since the time duration of the received pulses andthe time interval therebetween is a function of one relay operation orone relay restoration. With this invention a separate relay is operatedor released during each changeof-state of signalling.

This invention relates in general to pulse counters and in particular toa high-speed all-relay pulse counter. Its principal object is to providea new and improved pulse counter of the above character which is moreeconomical and reliable than prior-art pulse counters.

Pulse counters are known which comprise a finite series of relaysinterconnected in a chain and arranged to respond to a received seriesof impulses. At the end of-each series of impulses, one or more countingrelay is operated and contacts thereon provide an output indicative ofthe number of impulses in the received series. The repetition rate ofthe impulses received is directly related to the operate and releasetime of each counting relay. In addition, the maximum repetition rate islimited by the number of sequential operations or restoration of thecounting relays and associated control relays during each receivedimpulse.

These noted prior-art pulse counters have circuit configurations whichutilize at least one counting relay operation and at least one countingrelay restoration during either the pulse period or during theinter-pulse period, or

relay may be selectively connected for deciminal or twoout-of-fiveread-out, since only a single pair of output contacts is required foreach counting relay. Also, a counting during both periods. While theseknown counters employ various arrangements to reduce the operation andrestoration times of the relays to a minimum, nevertheless, someincrement of time is used, which time when added to other timeintervals, reduces the maximum counting rate obtainable.

According to the present invention, the above-noted counting ratelimitations of the prior-art counters are overcome by providing acounting chain in which only one counting relay operation or only onecounting relay restoration takes place during the pulse interval orinter-pulse interval. Under such conditions, the time duration of thereceived pulses and the time interval therebetween is a function of onerelay operation or one relay restoration. This results in a countingchain having an ideal pulse receiving rate. Thus, another object of thisinvention is to provide counting chain circuitry in which a separaterelay is operated or released during each change-of-state of signalling.

Another disadvantage of prior-art pulse counters resides in thearrangement wherein two or more counting relays are maintained operatedat the end of each received impulse. This requires the output or workcontacts on each counting relay to be interconnected with outputcontacts on another counting relay, thereby resulting in a complexoutput contact configuration.

chain may be provided for a combined decimal and twoout-of-fiveread-out. This minimum number of output contacts on a counting chainfurther increases the counting rate of the chain since it is well-knownthat a lightly loaded relay can be made to respond more rapidly than acounting relay having a large contact stack-up.

Still a further object is to provide inter-relay wiring within thecounting chain which utilizes a minimum of contacts and which does notrequire critically adjusted or specially wound relay coils. This is inkeeping with the above feature wherein the over-all spring stack-up oneach counting relay is kept to a minimum.

Another object is to provide a counting chain of relays having the aboveadvantages of high speed, simple output contact configuration and onerelay operation or restoration each change-of-state of signalling yetbeing reduced in number by providing a change-over relay which permitsthe counting relays to be re-used during a single digit train.

Other objects and features of the invention will become apparent and theinvention will be best understood when the specification and claims areread in conjunction with the accompanying drawing comprising a singlefigure showing a schematic diagram of the inventive counter.

Referring now to the drawing, the counting chain comprises fivecountin-g relays P1 to P5, 21 start relay A and a combined counting andswitch-over relay P6. When the counting chain is employed to count aseries of impulses in excess of five, the change-over relay P6 is usedas a counting relay.

The counting chain is provided with a group of control relays L, H, Sand AS for exercising control over various wires connected to thecounting chain relays A and P1 to P6. A pulse source INT is shown astelephone dial contacts for purposes of simplicity in describing theinvention. It is to be understood that any suitable pulse source couldbe used to generate the pulses which are received over input wire 11associated with relay L.

Two sets of output contacts are shown associated with relays P1 and PS.One set, comprising contact assemblies 0 five output. It is to beunderstood that only one contact assembly per set for decimal read-outcould be provided if the number of counting relays were increased tocorrespond to the number of impulses to be counted. To illustrate, ifonly five impulses were to be counted, only contact assembly 4 of relaysP1 to P5 would need to be provided. If seven impulses were to becounted, then two additional relays and wiring similar to that providedfor relays 'P1 to P5 could be provided. However, it has been chosen toillustrate the invention as using achange-over relay P6 so that countingrelays P1 to P5 could be reused to count impulses in excess of six.Nonetheless, it is clear that an indefinite number of relays could beprovided in one chain without a change-over relay.

The operation of the counting chain in responding to'a series of pulseswill now be described. For purposes of description, it is assumed thatthe pulse generator INT is selectively operated to generate any desirednumber of pulses in a series. Also it is assumed that key K comparableto hookswitch contacts is selectively operable to seize the countingchain for use by grounding input wire 11. All control relays andcounting chain relays are in an unoperated position as shown.

The pulses used to drive the counting chain are considered to beinterruptions of ground potential. Thus, the start or leading edge of apulse will be the disappearance of ground from input wire 11 and the endor trailing end of each pulse will be each reappearance of groundpotential thereon.

Assuming the hookswitch K is operated to seize the counting chain andthe digit 3 is dialed, the operation of the counting chain is asfollows:

The appearance of ground on wire 11 from dial INT closes an operatecircuit for relay L. Relay L operates and closes an operate circuit forrelay H.

Relay H operates and extends ground through its make contacts 2 andthrough break contacts 2 of relay S to wire 501. The ground on wire 501energizes the lower winding of relay A through break contacts 6 of relayP6.

Relay A operates and at its make contacts 1, prepares a locking circuitfrom wire 401 for itself and also prepares an operate circuit for relayP1.

At the start of the first pulse, ground disappears from wire 11 andrelay L is restored, removing ground from the winding of relay H andwire 501, and placing ground on wire 401 through make contacts 1 ofrelay H. Relay H remains operated for a time interval in excess of theinter-pulse interval of a series of impulses.

The noted ground on wire 401 locks relay A operated and closes anoperate circuit for both counting relay P1 and control relay S. Sincerelay A is now locked operated, the removal of ground from wire 501 isof no consequence at this time.

Relay S operates and at its contacts 2 prepares a circuit for groundingwire 601 and at its contacts 1 energizes relay AS.

Relay P1 operates from ground on wire 401 through contacts 2 of relay Aand locks operated to this ground through its own contacts 1. While notshown, the connection from the winding of each relay P1 to P6 to theirassociated contacts 1 could include a voltage dropping element to reducethe current used for holding these relays locked operated. At the sametime, contacts 3 of relay P1 prepares a second locking circuit foritself to wire 601.

Relay AS operates and at its contacts prepares a second path forgrounding wire 601.

At the end of the first pulse, when ground re-appears on wire 11, relayL re-operates and re-applies ground to relay H which remains operated.At this time, ground from contacts on relay L passes through makecontacts 2 of relay H to wire 601 which is connected to the lowerwinding of relay P1 through break contacts 3 of relays P2 to P6, andthrough make contacts 3 of relay P1, locking relay P1 operated. Also,ground is removed from wire 401, opening the operate and first holdingcircuit of relay P1; opening the locking circuit of relay A; and openingthe operating circuit of relay S. Relay A releases, relay P1 remainsoperated through its lower winding and relay S remains operated byvirtue of its slow-release characteristics. When relay A releases, itsbreak contacts 1 prepare an operate circuit for relay P2 on the start ofthe next impulse.

It can be seen that each change-of-state of the signal appearing on wire11 results in a different yet single relay operation occurring in thecounting chain. For example, on seizure, relay A operated; on the startof the first pulse, relay P1 operated; and at the end of the firstpulse, relay A restored. Therefore, the shortest pulse that can bereceived is limited by the speed of operation of a single relay P1 andthe shortest inter-pulse interval that is permissible is limited by therelease time of a single relay, relay A. As will appear hereinafter,this release time limitation will be for relays P1 to P5 on subsequentpulses.

On the start of the second pulse, relay L releases and it re-operates atthe end of the second pulse, thereby, causing relay P2 to operate at thestart of the second pulse and relay P1 to release at the end of thesecond pulse.

During the third and last pulse of the series of three pulses assumed tohave been dialed, relay P3 operates and relay P2 releases. Since nofurther pulses are forthcoming, relay L remains operated for an intervalof time in excess of the holding time of relay S and relay S releases.At this time, contacts 1 of relay S remove ground from relay AS andtransfer it to wire 301.

The ground on wire 301 is passed to either or both wires 101 and 201,depending on the connections at point P. Assuming wires 301, 201 and 101are connected together, ground passes over wire 101, through breakcontacts 4 of counting relays P4 and P6 and through make contacts 4 ofrelay P3 to deciminal output Wire 3, thereby indicating that threeimpulses have been received. Also, the ground on wire 201 passes throughmake contacts 6 and 7 of relay P3 to two-out-of-five output Wires 1 and2, which combination of wires indicate the digit 3 in a twoout-of-fivecode.

A short time later, relay AS releases and transfers ground from wire 601to wire 501. The removal of ground from wire 601 releases counting relayP3 and the appearance of ground on wire 501 energizes relay A ashereinbefore described for the seizure of the chain. The counting chainis now ready to receive a second series of impulses.

If the digit 7 or greater was dialed, relay P6 would operate on thestart of the sixth pulse. Relay P5 would release at the end of the sixthpulse by virtue of ground being removed from wire 401, and relay A wouldoperate from ground appearing on wire 601 and passing through makecontact 5 of relay P6, break contacts 3 of relays P1 to P5, and makecontact 6 of relay P6. This ground on wire 601 would also lock relay P6operated through its lower winding.

Relay P6 remains locked operated through its upper and lower windingssuccessively from ground appearing successively on wires 401 and 601, aslong as relay H remains operated from incoming pulses delivered to relayL.

Subsequent pulses in excess of six pulses re-operate relays P1 to P4successively as hereinbefore described for pulses one to four. Thefollowing chart illustrates the number of pulses received, the operatedor unoperated position of the relay L, the counting chain relays and theenergized output wires. The symbol X indicates an operated or energizedcondition.

Relays Output Pulses L A P1 P2 P3 P4 P5 P6 Dee. Code X X 1 0-1 X X X 20-2 X X End-3 X X 3 1-2 X 4 04 X X X 5 1-4 X X X 6 2-4 X X X X 7 0-7 X XX X X 8 1-7 X X X End- L X X 9 2-7 Start-10.. X X X End-l0 X X X 10 4-7Start] 1 X X X Alarm End-11 X X X Hold X At any time that the relay L isheld operated for an interval of time in excess of the hold-over time ofrelay S, alloperated counting relays are restored and relay A isoperated if not already in an operated position. This release of allcounting relays indicates the end of a series of impulses.

It will be noted that operation of relay P from ground on wire 401 as aresult of the beginning of the eleventh pulse will energize the alarmwire AL through contacts 2 of relay P6. The rectifier DR will precludethe holding ground of relay P5 from energizing the alarm wire during thereceipt of the sixth pulse when relay P6 is first operated.

In summary, as regards relays A and P1 to PS, the counting chainillustrated in the drawing operates a new counting relay on the start ofeach pulse, releases the last operated relay at the end of each pulseand has only one counting relay operated at any one time. It is to beunderstood that the same principle could be employed in extending thecounting chain to any desired number of counting relays. Also, theprinciple of employing a change-over relay to permit re-use of thecounting relays could also be extended to apply to a counting chain forcounting any desired number of impulses. Still further the principle ofemploying a changeover relay as a counting relay could be applied tochains arranged to count any desired number of pulses.

The wiring shown at point P, as hereinbefore noted could be selectivelyconnected to either wire 101 or 201 and the output contact configurationassociated with the unconnected one of the Wire 1011 or 201 could beeliminated from the disclosed counting chain. In this manner, a countingchain providing decimal output only, a twoout-of-five output only, or acombination thereof can readily be provided. In this respect, theterminals associated with the counting relay output contacts could beterminated on a terminal board and jumpering provided to convert thecounting chain from one type of readout to the other without alteringthe relay internal wiring.

While I have described my invention in conjunction with specificapparatus and circuitry it is to be clearly understood that thisdescription is made only by way of example and not as a limitation onthe scope of the invention.

I claim:

1. An impulse counting circuit for counting the number of impulses in aseries of received impulses, a chain of counting relays, means foroperating and restoring said relays in response to said received seriesof impulses with only one counting relay being operated at the beginning and only one being released at the end of any received impulseseries, the operate time of any relay being determinative of theshortest impulse capable of being counted by said circuit and therelease time of any relay being determinative of the shortestinter-impulse interval of any series of impulses capable of beingcounted by said circuit.

2. An impulse counting circuit as set forth in claim 1 wherein means areprovided on said counting relays for selectively indicating in decimalform, in coded form and in both decimal form and coded form, the numberof received impulses.

3. An impulse counting circuit as set forth in claim 1 wherein thenumber of counting relays operated at any one time does not exceed twoand wherein only one counting relay is operated at the end of anyreceived impulse.

4. An impulse counting circuit as set forth in claim 1 wherein theoperate time intervals of said relays is unequal to the release timeintervals of said relays.

5. An impulse counting circuit for counting the number of impulses in aseries of received impulses, comprising a chain of counting relays,means for operating said relays in succession in response to receivedimpulses with a separate relay operating during each impulse duration,means for successively restoring said relays in the order of theiroperation with a separate relay restoring during the interval followingeach received impulse after the second received impulse, whereby onlyone counting relay is in operated condition at the end of any receivedseries of impulses.

6. An impulse counting circuit for counting the number of impulses in aseries of received impulses, comprising a chain of counting relays eachhaving an oper ate winding and a hold winding, means for closing anenergizing circuit to the operate winding of said relays in successionin response to the start of each impulse, means for energizing theholding winding of each lastoperated relay in response to the end ofeachreceived impulse and for opening the last-closed energizing clrcuit,and means on each last-operated relay for maintaining the said operatewinding thereof energized throughout the duration of the last receivedimpulse.

7. An impulse counting circuit as set forth in claim wherein the saidmeans for closing an energizing circuit to the operate winding of anycounting relay succeeding the first includes contact means on animmedlately preceding counting relay.

8. An impulse counting circuit as set forth in claim 6 wherein the saidmeans for opening the last-closed energizing circuit for the operatewinding of any relay succeeding the first includes means for restoringthe immediately preceding counting relay.

9. In an impulse counting circuit for counting the number of impulses ina series of received impulses, a chain of relays including a pluralityof counting relays and a control relay, means for operating said controlrelay to prepare said counting relays for operation, means responsive tothe start of each received impulse for operating a different one of saidrelays and means responsive to the end of each received impulse forrestoring a different one of said operated relays whereby the number ofoperated relays of said chain does not exceed two and only one relay ofsaid chain is operated at the end of said series of impulses.

10. An impulse counting circuit as set forth in claim 9, means operableresponsive to the end of the impulse operating the last relay of saidchain for re-operating said control relay and for maintaining said lastrelay operated, means responsive to the start of each impulse in excessof the number of counting relays for re-operating a diiferent one ofsaid restored relays, and means responsive to the end of each of thelast-said impulses for restoring a different one of said re-operatedrelays.

11. An impulse counting circuit for counting the number of impulses in aseries of received impulses, a chain of counting relays, means foroperating the first relay of said chain responsive to the start of thefirst received impulse and for operating the second relay of said chainresponsive to the start of the second received impulse, means forrestoring said first relay responsive to the end of said second receivedimpulse, and means for thereafter operating a different relay on thestart of each succeeding received impulse and restoring the previouslyoperated relay at the end of each received impulse, whereby the numberof chain relays operated at any one time does not exceed two and whereinonly one relay is operated at the end of any received impulse.

12. An impulse counting circuit for counting the number of impulses in aseries of received impulses, a chain of counting relays fewer in numberthan the number of received impulses in a series, means for operatingsaid relays in succession in response to a number of received impulsesequal in number to said relays with a separate relay operating duringeach impulse interval of said incoming impulses, means for successivelyrestoring said relays preceding the last in the order of their operationwith a separate relay restoring during the interval following eachreceived impulse after the second received impulse, means forre-operating said relays in succession in response to received impulsesgreater in number than the number of relays with a separate relayoperating during each impulse interval, and means for restoring saidre-operated relays preceding the last re-operated relay whereby the lastrelay of the said chain and one additional chain relay are operated atthe end of any received impulse greater in number than the number ofchain relays.

'8 References Cited UNITED STATES PATENTS 2,768,335 10/1956 Coley 3l71402,942,159 6/1960 Polley 317140 2,954,511 9/1960 Jackel 317-140 DARYL W.COOK, Acting Primary Examiner.

G. MAIER, Assistant Examiner.

1. AN IMPULSE COUNTING CIRCUIT FOR COUNTING THE NUMBER OF IMPULSES INSERIES OF RECEIVED IMPULSES, A CHAIN OF COUNTING RELAYS, MEANS FOROPERATING AND RESTORING SAID RELAYS IN RESPONSE TO SAID RECEIVED SERIESOF IMPULSES WITH ONLY ONE COUNTING RELAY BEING OPERATED AT THE BEGINNINGAND ONLY ONE BEING RELEASED AT THE END OF ANY RECEIVED IMPULSE SERIES,THE OPERATE TIME OF ANY RELAY BEING DETERMINATIVE OF THE SHORTESTIMPULSE CAPABLE OF BEING COUNTED BY SAID CIRCUIT AND THE RELEASE TIME OFANY RELAY BEING DETERMINATIVE OF THE SHORTEST INTER-IMPULSE INTERVAL OFANY SERIES OF IMPULSES CAPABLE OF BEING COUNTED BY SAID CIRCUIT.